PSLE
At first, Tammy had an equal number of black and green marbles . She gave away ²₃ of her black marbles and some green marbles. In the end, she was left with ²₅ of her marbles. What fraction of the green marbles did Tammy give away?

	Black	Green	Total
Comparing black marbles and green marbles at first	1x3x5 = 15 u	1x3x5 =  15 u	2x3x5 =  30 u
Before	3x5 = 15 u	15 u	5x6 = 30 u
Change	- 2x5 = - 10 u	- 8 u	- 2x6 = - 18 u
After	1x5 = 5 u	7 u	3x6 = 12 u

After1_x5 =
5 u
7 u3_x6 =
12 u
The number of black marbles at first is repeated. Make the number of black marbles the first the same. LCM of 3 and 1 is 3.

The total number of marbles at first is repeated. Make the total number of marbles at first the same. LCM of 6 and 5 is 30.

Number of green marbles that Tammy was left with
= 12 u - 5 u
= 7 u

Number of green marbles that Tammy gave away
= 15 u - 7 u
= 8 u

Fraction of the green marbles that Tammy gave away = ⁸₁₅

Answer(s): ⁸₁₅